LEED V3

LEED

Written by R. Kirk Johnson, AIA, LEED AP

USGBC SET TO RELEASE THE NEXT GENERATION OF THE LEADING STANDARD

LEED 2009, the next generation of the international leading sustainable design certification standard is approaching release this month. As part of the more comprehensive LEED v3 program, the updated rating system incorporates a new credit weighting system and features considerable advancements in procedures, credit alignments, clarifications, and standards. Initially, LEED 2009 conglomerates existing New Construction, Core and Shell, Commercial Interiors, Existing Buildings, and Schools standards into a cohesive reorganized library system. According to USGBC, the new standard concentrates upon several key individual elements such as credit alignment and harmonization, prerequisite and credit updating, codified development cycle, human impact credit weighting differentiation, and added regionalization improvements. Primarily, LEED 2009 provides a reorganization of the existing standards with some notable advancement to the standards.  Some of the updates are listed in the following.

CREDIT WEIGHTING AND DIFFERENTIATION

One of the first noticeable improvements to the rating system is the inclusion of a new consistent harmonized credit numbering system. In previous iterations of individual standards, each particular flavor of LEED had variant scales of credits that were required in order to reach building certification. The new LEED 2009 harmonizes all of the existing rating systems into a consistent 100 point value based configuration with an additional 10 bonus point scale opportunity. In order to accomplish this restructuring step, existing credits were analyzed for common elements and ranked according to their environmental impact as determined by anecdotal evidence, exhaustive research, and multiple existing scientific analysis tools such as the EPA TRACI (Tools for the Reduction and Assessment of Chemicals and other Impacts) life-cycle analysis criteria toolset. With this overriding development strategy, LEED credits positively impacting the environment, particularly in response to items such as climate change and energy efficiency, are weighted with more available point options within the new rating system. Additional regionalization bonus points specific to a projects given environmental zone were also incorporated into the system bringing the total available bonus point structure to ten. All standards will now utilize the 100+ numbering system.

CREDIT ALIGNMENT AND HARMONIZATION

Another tangible component of LEED 2009 is the thorough alignment of the credit structure into fundamental common denominators and the incorporation of clarifying information that was previously only provided in various independent Credit Interpretation Rulings. This “bookshelf” concept of credit consolidation provides a universal  library pool of credits common to all LEED rating systems, a semi-universal library of credits available to a majority of rating systems, and a smaller specific library category applicable to specific market system credits. With this metaphor, each credit is similar to a book within a library. As a result of the alignment and consolidated, a more cohesive set of documentation and implementation tools have been provided to users of the LEED rating systems.

CONTINUOUS DEVELOPMENT CYCLE

Although not specifically obvious in the credit worksheets, one of the primary foundational goals of the alignment was to provide a workable infrastructure for continuous improvements to the development cycle. In particular, this constituted codifying a predictable organized development cycle designed to influence continuous improvements into the LEED standards and to provide the opportunity for the market to participate in the process. This action bases the evolution of the standard around industry familiar improvement methods by which other standards such as building codes are developed and forms the implementation methodologies around a set release schedule.

REGIONAL PRIORITY CREDITS

One of the more significant elements within the new standard focuses upon the inclusion of additional incentives to the LEED Innovation & Design bonus points. Currently, the incentives provide opportunities for exemplary performance and innovation.  LEED 2009 expands these offerings to include additional bonus points for region specific credits that are considered important for individual climatic areas. For instance, a dry arid region may add additional bonus credits for water conservation that are above and beyond the current standards. These particular credits are in the process of evaluation and will be provided after much additional input from individual USGBC Chapters, Regional Councils, and the LEED Steering Committee. After inclusion into the standard, users will be able to utilize credits from a region specific available listing.

EXEMPLARY PERFORMANCE

Another element of LEED 2009 is the reorganization and recognition of exemplary performance bonus components.  Presently within the current standards, a maximum of 4 points can be obtained for exemplary performance under the Innovation and Design Credit options. These credits can be achieved by providing demonstrative evidence that the project attained considerable advancement over and above the base credit requirement.  In many cases this involved a doubling of the credit requirement and in other instances it entailed reaching the next percentage threshold for the individual credit. LEED 2009 continues to allow for exemplary performance categories with similar criteria but decreases the available points to a maximum of three thereby encouraging the adoption of other green building innovation elements with the other two credits. Overall, the implementation of the regionalization categories and the reorganization of the existing innovation and design credits double the bonus point opportunities that were previously available under existing standards.

NOTABLE CREDIT MODIFICATIONS

Some noteworthy credit amendments to LEED 2009 beyond the criteria listed above are listed in the following.
• Water Conservation: A new prerequisite was added to the Water Efficiency section requiring a minimum 20% improvement over the 1992 water efficiency regulation.  The threshold for WE c3.1 has been elevated to 30% and WE c3.2 has increased to a 40% minimum threshold.
• Energy Optimization: Minimum energy performance requirements were increased by the adoption of the 2007 version of the ASHRAE 90.1 Regulation. This adoption is required in the minimum 2 point prerequisite and also in the EA c1 Energy Optimization credit areas. The new ASHRAE 90.1 increases the energy performance requirements for buildings. However, the percentage thresholds within the Energy Optimization credits have been expanded from 10 to 19 available points and the minimum prerequisite requirement has been reduced to 10 percent. The overall effect with the new energy requirement and percentage adjustments will vary depending upon building specific design components, but in general will be more stringent than previous iterations of the standards.
• Mixed Use Projects: Additional language has been added to the SS c2 Development Density and Community Connectivity to address mixed use projects.
• Alternative Transportation: Complimentary to significantly variant weighted point options, additional clarifying language has been included into the Alternative Transportation sections of LEED 2009.
• Heat Island Reduction: Considerable clarifications, derived primarily from Credit Interpretation Rulings, have been added to SS Credit 7.1 Heat Island Reduction: Non-roof.  Additional weighted SRI calculation methods are added to SS Credit 7.2 Heat Island Reduction: Roof
• Low -Emitting Flooring Materials: EQ Credit 4.3 has been expanded to include all flooring components beyond the carpet requirement of the previous standard.
• Daylighting: Considerable modifications have been applied to EQ Credit 8.1 Daylight & Views expanding the documentation and implementation of daylighting into buildings.
Registration

LEED 2009 is scheduled to be released in March. Educational elements such as Reference Guides, seminars, and webinars will be available beginning in March. Users of previously registered projects under the current LEED Standards will have the option to continue using the initial registration standard or to upgrade to the new reference standard during the LEED 2009 transition time.  Each project is encouraged to run detailed analysis to determine which option best fits the project requirements. Volume registration, submittals, and certification options are scheduled to go live beginning in May. The completed phase rollout of LEED 2009 rating system, educational components, registration criteria, and new AP exams is scheduled to be completed by September 1.